Interleukin 31 (IL31) is a cytokine mostly produced by Th2 cells and understood to be involved in promoting skin disease, such as pruritic and other forms of allergic diseases (for example, atopic dermatitis). IL31 functions by binding its receptor and activating downstream activities, such as activation of JAK1, and is thought to cause many of the clinical problems associated with dermatitis and other disorders.
Companion animals such as cats, dogs, and horses, suffer from many skin diseases similar to human skin diseases, including atopic dermatitis. However, the IL31 sequence is divergent between human, cat, dog, and horse. There remains a need, therefore, for methods and compounds that can be used specifically to bind companion animal IL31 for treating IL31-induced conditions and for reducing IL31 signaling.